Re: [PATCH 2/3] Fix autoprofiledbootstrap

["Bin.Cheng" <amker.cheng@gmail.com>]

On Mon, Jan 14, 2019 at 4:20 PM Andi Kleen <andi@firstfloor.org> wrote:
>
> From: Andi Kleen <ak@linux.intel.com>
>
> autoprofiledbootstrap fails currently with
>
> In file included from ../../gcc/gcc/hash-table.h:236,
>                  from ../../gcc/gcc/coretypes.h:440,
>                  from ../../gcc/gcc/ipa-devirt.c:110:
> In static member function 'static void va_heap::release(vec<T, va_heap, vl_embed>*&) [with T = tree_node*]',
>     inlined from 'void vec<T>::release() [with T = tree_node*]' at ../../gcc/gcc/vec.h:1679:20,
>     inlined from 'auto_vec<T, N>::~auto_vec() [with T = tree_node*; long unsigned int N = 8]' at ../../gcc/gcc/vec.h:1436:5,
>     inlined from 'vec<cgraph_node*> possible_polymorphic_call_targets(tree, long int, ipa_polymorphic_call_context, bool*, void**, bool)' at ../../gcc/gcc/ipa-devirt.c:3099:22:
> ../../gcc/gcc/vec.h:311:10: error: attempt to free a non-heap object 'bases_to_consider' [-Werror=free-nonheap-object]
>   311 |   ::free (v);
>       |   ~~~~~~~^~~
> ../../gcc/gcc/vec.h:311:10: error: attempt to free a non-heap object 'bases_to_consider' [-Werror=free-nonheap-object]
> cc1plus: all warnings being treated as errors
>
> The problem is that auto_vec uses a variable to keep track if the vector
> is on the heap or auto. Normally this gets constant resolved, but only
> when the right functions are inlined. With autofdo for some reason
> the compiler decides to not inline these vec functions, even though
> they are marked as "inline"
A comment not closely related to this patch.  We observed the same
inline behavior in which perf data is inadequate, sometime it has
non-trivial impact on kernel compilation.  We have patch fall back to
guessed profile count if the profiled count is of low quality.  Will
send it out in GCC10.

Thanks,
bin
>
> Mark them as ALWAYS_INLINE instead.
>
> gcc/:
>
> 2019-01-14  Andi Kleen  <ak@linux.intel.com>
>
>         * vec.h (using_auto_storage, release): Mark as ALWAYS_INLINE.
> ---
>  gcc/vec.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/vec.h b/gcc/vec.h
> index 407269c5ad3..1f5b78b1fac 100644
> --- a/gcc/vec.h
> +++ b/gcc/vec.h
> @@ -1664,7 +1664,7 @@ vec<T, va_heap, vl_ptr>::create (unsigned nelems MEM_STAT_DECL)
>  /* Free the memory occupied by the embedded vector.  */
>
>  template<typename T>
> -inline void
> +ALWAYS_INLINE void
>  vec<T, va_heap, vl_ptr>::release (void)
>  {
>    if (!m_vec)
> @@ -1940,7 +1940,7 @@ vec<T, va_heap, vl_ptr>::reverse (void)
>  }
>
>  template<typename T>
> -inline bool
> +ALWAYS_INLINE bool
>  vec<T, va_heap, vl_ptr>::using_auto_storage () const
>  {
>    return m_vec->m_vecpfx.m_using_auto_storage;
> --
> 2.19.1
>